About 200m from the cable car station in Villars, heading along the road back towards col de la croix, take the les bouqetins path towards Roc 'dorsay, from their up on to Grand Cham, across Ridge to Petit Cham,then head down and back up the valley towards the train station, but turn head up Chax Ronde. Down again and spend the night wild camping at lac noir / chavoness?
From here 2 options:Option 1- i'd follow the chairlift to diablarets from villars across the nature reserve, this I guess would take a day. Once in diablarets you would have a few options, but I'd probably aim to end up either in the village or Vers d'iglise, if the latter I would aim to take the train or walk round the valley back to diablarets town centre.
Option 2 - I would camp on chaux ronde and in the morning head down the back towards Barboulouse, down the golf course and then towards croix des chaux on the summit?